Accidental needle sticks with new unused needle can cause injury and render the needle unfit for further use. Accidental needle sticks with a used needle can transmit disease. As a result, most prior art needle assemblies have a needle shield. Some prior art needle shields define a rigid sleeve that can be manually telescoped over a needle cannula. This procedure requires a healthcare worker to hold the syringe barrel in one hand and the shield in the other. Some medical procedures require the application of pressure to the penetration site after the needle has been removed. Thus, healthcare workers are often unable to use both hands for shielding the needle cannula. In these situations, workers merely deposit the used medical implement on a nearby surface with the intention of shielding at a more convenient time. However, until the needle is shielded or properly disposed of, it presents a potential danger to other people.
A needle shield which is hinged near the base of the needle has the advantage of allowing one handed needle reshielding. Thus providing the opportunity for reshielding, under most circumstances, immediately after use. Accordingly, a number of prior art needle shield assemblies have been developed that include such needle shields.
Various means have been provided for locking a hinged needle shield in the closed, needle protecting, position. Deflectable members have been provided in the needle shield for engaging the needle upon shielding and preventing subsequent unshielding of the needle. Such members trap the needle within the needle shield. Locking has also been accomplished by locking engagement of the needle shield with structure near the base of the needle.
Although hinged needle shields are known in the art, there is still a need for an improved hinged needle shield that is automatically locking, cost effective, easy to manufacture and having improved safety features.